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Genus Gibbocarina

Shell is elongated-pyriform, with the lateral sides tapering towards the aperture, with a hollow tuberous keel surrounding the entire posterior end of the shell. Shell hyaline or slightly yellowish, composed of circular to elongated shell plates, probably recycled from euglyphid testate amoeba prey. Members of this genus differ from those in the genus Nebela by the strongly elongated shape of the shell, the presence of a hollow keel and in most cases a larger size. From the members of Longinebela, they differ mainly by the presence of a keel. Gibbocarina may be confused with Planocarina, although in the latter the keel is flat, while in Gibbocarina it is hollow (the difference is very obvious when seen in profile). Type species: Gibbocarina galeata (Penard, 1890)